Over 50,000 users leave South Korean telecom KT in four days

Over 50,000 KT customers left the company within four days after it waived early termination penalties in response to a recent data breach, according to industry sources.

KT is South Korea’s second-largest mobile carrier.

From December 31, 2025 to January 3, 2026, 52,661 users switched to other providers, with over 70% choosing SK Telecom.

On January 3, 21,027 customers left KT, and 13,616 of them joined SK Telecom.

SK Telecom, the country’s largest mobile carrier, has been actively seeking to attract KT users, including those who previously left after SK Telecom’s own hacking incident last year.

🔗 Source: Yonhap

🧠 Food for thought

Implications, context, and why it matters.

Four-day departures make up a small slice of KT’s mobile base with limited near-term financial hit

Industry sources count 52,661 departures over four days, a small slice of KT’s mobile base. The figure looks dramatic as a raw number. It may match typical monthly churn in competitive markets.
Over 70% went to SK Telecom. SK Telecom is the country’s largest mobile carrier with broader infrastructure and stronger brand pull. Even if many leavers used premium plans, KT’s quarterly wireless revenue likely sees only a modest hit in total.

Korean Mobile Virtual Network Operators (MVNOs) and international embedded SIM (eSIM) platforms can ride higher switching intent with targeted port-in campaigns

The penalty waiver creates a rare easy window for MVNOs across brands tied to KT, SK Telecom, and LG U+. LG U+ is South Korea’s third-largest mobile carrier. Price-focused shoppers during contract changes respond well to subsidized device bundles. Targeted port-in campaigns (promotions that encourage customers to transfer their existing phone numbers) can lift sign-ups.
International eSIM providers that serve Korean enterprise clients and frequent travelers can move faster on carrier partnerships now. Security minded business users may seek alternative connectivity after data breach headlines. That opens demand outside normal consumer churn cycles.